addition to the alarm lights, there are status lights at the
of control and monitoring. Notice also that the EPCC on
EPCC for each GTGS.
the CG-47 class ships has an additional section for the
400-Hz system.
Electrical Distribution System Monitoring
We will briefly discuss the following control
systems operated from the EPCC:
The generator status panel at the EPCC provides
1. GTGS monitoring
meter displays and alarms for monitoring the output of
the GTGSs. An additional section of this panel is for
2. Electrical distribution system monitoring
shore power monitoring. The electrical distribution
3. Circuit breaker control
system provides monitoring by using meter displays and
alarm lights. The operator can test the conditions of
4. Gas turbine control
shore power by using the phase sequence meter and its
5. Generator control
associated switch.
6. System configurations
Circuit Breaker Control
7. Load shedding
8. Turbine overload protection system (TOPS)
The EPCC provides centralized control and
monitoring of the generator circuit breakers, bus tie
9. 400-Hz power system
breakers, and load center breakers. The push-button
We will provide only an overview of these systems. For
indicators used to operate these breakers are located on
a detailed description of the operation of these systems,
the EPCC mimic panel. Control of circuit breakers from
we recommend you consult the EOSS, EOP, and specific
the EPCC is enabled only when the generator control
technical manuals for the equipment and systems of
switches at the switchboards are in the REMOTE
position.
your ship.
Circuit breaker control at the EPCC can be divided
GTGS Monitoring
into two categories: operator initiated and logic
initiated. Operator-initiated circuit breaker control is
Each GTGS has sensors to provide remote
provided at the mimic panel with the push-button switch
monitoring of the gas turbine engine and the generator.
indicators. Logic-initiated circuit breaker close
commands originate when the EPCC is in the automatic
The sensor information is sent to the EPCC in any one
operating mode. Bus tie breakers 3S-1S and 3S-2S are
of the three following ways:
the only breakers with auto trip commands. The
1. Directly from alarm contact switches
commands isolate switchboard No. 3 if all three
generators are in parallel for more than 2 minutes.
2. Through alarm detector circuits in the generator
control panel
Gas Turbine Control
3. Through the propulsion and auxiliary machinery
information system equipment (PAMISE) via
Gas turbine control available at the EPCC consists
the signal conditioning enclosure (S/CE) No. 1
of gas turbine start and stop control and gas turbine
The PAMISE provides the high vibration alarm and
frequency control.
parameter information for the demand display indicator
Manual GTGS control available at the EPCC
(DDI).
consists of a START push button, a STOP push button,
There are several GTGS alarms at the EPCC that
and a HP AIR/LP AIR GTRB start mode selector switch.
The start controls are enabled only when the control
indicate abnormal conditions to the operator. With two
transfer switch at the generator control panel and
exceptions, these alarms are initiated by contact sensors
switchboard are in the REMOTE position. The operator
at the GTGS. The two alarms that are not initiated by
initiates a start by selecting the type of air (HP or LP) to
the contact sensors are the vibration high alarm and the
use and depressing the START push button.
high turbine inlet temperature (TIT) alarm. The
vibration high alarm is generated by an alarm detector
The EPCC STOP push button is not affected by the
in S/CE No. 1. The high TIT alarm is initiated by a TIT
control transfer switches. When this button is depressed,
a signal is sent to the turbine stop relay at the
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